Characterization of Cellulose-Nanofiber-Modified Fibrillated Lyocell Fiber Separator

A fibrillated lyocell fiber-based separator was prepared using lyocell fibers and was modified with cellulose nanofibers. The effects of the cellulose nanofiber addition on the tensile properties, electrical properties, pore structure, liquid absorption properties, and equivalent series resistance of the separators were studied. It was found that adding an appropriate amount of cellulose nanofibers to the fibrillated lyocell fiber separator can improve the tensile strength, elongation at break, breakdown voltage, and equivalent series resistance value of the separator; reduce the pore size and porosity of the separator; and improve the pore size distribution. Moreover, the separator modified with 4% cellulose nanofibers yielded a favorable combination of properties, with a tensile strength of 0.645 kN/m, a mean flow pore diameter of 0.771 mu m, a porosity of 88.4%, a capillary rise in paper of 30.7 mm/10 min, and an equivalent series resistance value of 2.46 Omega.